About 18,400 machinists are scheduled to vote Thursday on a three-year contract offer that, if approved, would allow Boeing to swiftly reopen its commercial airplane assembly facilities in the Puget Sound area, Gresham, Ore., and Wichita, Kan.

The new proposal gives workers a nearly 17 percent boost in pension payouts and guarantees retiree medical benefits for new hires. It assures that health care premiums remain the same as the current contract. But it calls for no general wage increase, instead opting for lump sum bonuses totaling about $11,000 over three years. And it takes away a previously offered provision that would have given workers pay incentives based on corporate financial performance.

Leaders of Machinists District Lodge 751 in Seattle say the deal is "a victory for working families across the country" that addresses the issues most important to its members, who average 49 years of age and make about $59,000 a year.

The company says the total cost is similar to its previous offer, and analysts say the resolution allows the company to quickly regain the momentum it needs to continue its heated battle with rival Airbus.

Investors appeared to welcome the tentative agreement, sending Boeing shares up $1.47, or 2.3 percent, to close at $64.67 Monday on the New York Stock Exchange. In the last 52 weeks, shares have traded between $48.10 and $68.38.

The new proposal comes just over three weeks after the machinists walked off the job after union leadership deemed the company's previous offer "insulting." Both sides had insisted since then that they were miles apart and unsure when a happy medium could be reached.

But Aboulafia said the surprise announcement Sunday that a proposal had been brokered could mean that the two weren't nearly as far apart as public posturing would suggest.